Efficacy and safety of tazemetostat in patients with refractory/relapsed follicular lymphoma or diffuse large B cell lymphoma: Systematic review and meta analysis.

e19064 Background: Around 20-25% of individuals diagnosed with follicular lymphoma (FL) do not respond to the first line of treatment. There has been no comprehensive analysis of clinical trials to enhance the evidence for clinical decision-making. In 2020, the FDA granted approval for Tazemetostat to be used in cases of refractory FL. Our research analyzed the effectiveness and safety of Tazemetostat as either a single therapy or in combination therapy for patients with relapsed/refractory (R/R) FL and diffuse large B-cell lymphoma (DLBCL) who had undergone at least two prior chemotherapy agents. Methods: We selected Non-Randomized Controlled trials assessing Tazemetostat, either as mono therapy or in combination with other therapies in R/R FL and DLBCL from MEDLINE/PubMed, EMBASE, clinicaltrials.gov, and the Cochrane Library. Outcomes measured were Objective Response Rate (ORR), progression free survival (PFS), Duration of Response (DOR), Treatment Related Adverse Events (TRAE), and Treatment Related Serious Adverse Events (TR-SAE). Publication bias was assessed using a funnel plot and meta-analysis was performed by Comprehensive Meta-Analysis Software version 5. Pooled estimates for efficacy and safety outcomes were calculated using random effect models, and heterogeneity was assessed with the I² statistic. Results: Eight studies were included with 306 participants. In the FL group, the ORR was 64.2% (95% CI: 48.9–77.7%; p =0.001, I² = 73%) indicating good efficacy. The PFS analysis revealed a mean effect size of 9.68 months (95% CI: 4.46–14.90; p < 0.001, I² = 99%). The DOR showed a pooled value of 84.5% at 12 months from 2 studies. The ORR in the DLBCL was 59.4(95% CI: 23.9–87.2%; p <0.001, I² = 84). Overall, Tazemetostat was well tolerated as evident by the TRAE >grade 3 at 13.8 % (95% CI: 6.8–26.1, I² = 15%) and TR-SAE at 5.4 % (95% CI: 2.8–10.2, I² = 0%). In summary, R/R FL and DLBCL responds well to Tazemetostat in terms of ORR, PFS, and DOR. Conclusions: Relapsed/refractory FL and DLBCL responds well to Tazemetostat in terms of ORR, PFS, and DOR, with a relatively low incidence of severe adverse events making it a viable and promising treatment option. Additional studies are necessary to confirm these findings and enhance treatment approaches.